Review Article: Darwin on Trial, by Phillip Johnson

The supposed virtues of looking at evolutionary biology through the eyes of a legal scholar shows up frequently in newspaper reporter's discussions of Darwin on Trial. But why should we assume lawyers would have a special insight into evolution, or science in general?

Science is a way of understanding natural phenomena. Law is a way of resolving conflicts, or controversy. The two disciplines have different goals. Now, it might be interesting to have a lawyer use the tools of his trade to resolve a controversy about, say, whether birds are descended from dinosaurs, or how much of the fossil record is explained by punctuated equilibria vs gradualism, though because of differences between the approaches of law and science, nothing significant is likely to come of it. It would be fun entertainment, much as are the "Court of Historical Review" mock "trials" where it is "determined" in a court of law such things as who first discovered America.

These subjects are at least controversial. But Johnson is applying his controversy-resolving skills to a non-controversy. That evolution occurred is, in science (if not in the general public) no more controversial than that the earth goes around the sun. This is not to say that many people don't "disbelieve" that evolution occurred, but this view is either out of ignorance (the majority of the American public) or out of religious zeal (the "scientific" creationists.) Johnson admits that the "critics" of natural selection he cites are not antievolutionists — yet he then uses their criticisms to try to disprove that evolution occurred. Whether evolution occurred or not is just not a debated question in mainstream science. But Johnson makes it appear that it is, and applies his forensic skills, inappropriately, to persuading us of this idea.

Science is played by rules that scientists have worked out over the years, and Johnson's rules are different. It is as if I and my colleagues are out on the field with our mitts and bats, and the pitcher is warming up in the bull pen, and Johnson comes out dribbling a basketball, demanding to play with us. Basketball is a fine game, but we're not playing that game, and if Johnson wants to play, he has to play by our rules.

His rules, as will be clear to anyone who reads his book, impose narrow Baconian, direct observational, direct experimental research design constraints on science, exactly as do the young-earth creationists. Unfortunately, the general public, even more ignorant of the philosophy of science than Johnson, is as Baconian as he is (or more so), finding perfectly comprehensible the accusation that "neither evolution nor creationism are scientific because no one was there to see it happen."

Law, Theory and Fact

Lawyers and scientists use many of the same terms, but use them very differently. Words like "law," "theory," and "fact" provide some of the biggest differences, but by no means all. "Law," "theory," and "fact," are also used differently by members of the general public — further confusing the issue.

To modern scientists, the term "law" refers to a descriptive generalization, "theory" to an explanation of a phenomenon. Theories are more important than laws, because they are explanations of phenomena, rather than descriptions. Thus the Theory of Relativity is a "bigger deal" than the Laws of Thermodynamics, regardless of the usefulness of the latter.

"Law" in the legal profession, of course, means a body of prescriptive statements which regulate people's behavior. Laws are slow to change. Some of the legal statements that govern us in the US today, in fact, were first formulated in the 1300's. Laws are not to be broken; they have great status, and are not mere "descriptive generalizations" as they are in science. Members of the general public are more attuned to the legal than to the scientific use of the term "law." Most laypersons believe, erroneously, that scientific laws are more important than theories, that scientific "laws" cannot be "broken," and that a law, once established, cannot be altered: it is scientific "Truth."

Similarly, a legal "theory" differs from a scientific one. A legal theory refers to the approach used by a lawyer for analyzing or developing a particular case. It is based on relevant law, the facts of the case, an estimation of the opposing side's strategy, and the measures that can best be used to counter that strategy. A good lawyer may use a different "theory" for every case he tries, even if the "law" (e.g., a larceny statute) is the same. Theories are important tools in the legal profession, but they are tools only. Laws obviously are treated with more respect.

There are certainly some parallels between a legal theory and a scientific one. A scientific theory has to be based on "the law" in the sense that it builds upon already accepted theory, and the rules of logic with which component statements of a theory are related to one another. But from here on, things sharply diverge. In a lawsuit, a complaint is drafted, outlining a case, which includes a listing of "facts" which the lawyer will prove to the court's satisfaction. Facts create issues to be decided in the courtroom. Laws are applied to the facts to generate relevant conclusions; the practice of law, again, is to resolve conflict. In the answer to the complaint, the other side either admits the facts, denies the facts, or leaves them for later argument. Once the defense has admitted that Mr. Boddy was found in the parlor with a lead pipe, then these facts are immutable, and are no longer disputed.

Contrast this certainty with the impermanence of a scientific "fact!" Many scientists don't even use the Baconian word "fact" with its implications of certainty, and instead speak of "observations." Facts have the least "authority" of this fact, law, and theory triumvirate, whereas they are primary in law. A scientific fact, first of all, can (and does) change, which is definitely not the case with a legal fact, once agreed upon. It was a fact for over a decade, for example, that Homo sapiens had 48 chromosomes, though now we feel confident that there are 46. Facts also change with theories, because theories explain facts, and also change with new methodologies, themselves driven by theory. Furthermore, there is scarcely ever a situation wherein scientists on opposite sides of a theoretical issue will ever sit down and agree beforehand on what the facts are! Science, for good or ill, is a far messier process than law.

But creationists, ever the Baconians, criticize evolution for not being science because "we keep changing our minds about what happened." Johnson himself criticizes evolutionary biology for changing with new information, for example, accusing the supporters of punctuated equilibria of trying to "save" evolutionary theory when the fossil record "refuted" gradualism.

"...paleontologists clearly needed to find a theory that would allow them to report their projects as successful, but they felt constrained to operate within the boundaries of the neo-Darwinian synthesis. What was required was a theory that was saltationist enough to allow the paleontologists to publish, but gradualistic enough to appease the Darwinists. Punctuated equilibrium accomplishes this feat of statesmanship by making the process of change inherently invisible. You can imagine those peripheral isolates changing as much and as fast as you like, because no one will ever see them" (p. 61).

He doesn't quite "get" punctuated equilibrium, but what I want to focus on instead in this passage, is a profound misunderstanding of how science works.

In science, it's OK to change your mind about an explanation if you get new data, or if you are able to look at old data differently. The goal is explanation through theory, and, as mentioned before, we know enough about the fallibility of empirical explanations to realize that "truth" is only a goal.

The differences in the use of the term "fact" offer an exceptionally sharp contrasts between the legal and the scientific use of terms, and these differences show up clearly in Johnson's book.

The use of the term "theory" in law points out clearly to us laypeople the adversarial nature of law. The game, after all, is for my champion to get on his horse and ride against your champion, and the most skillful proxy wins. Although science (and scientists) can certainly be adversarial, the nature of competition among scientific ideas contrasts sharply with competition between lawyers in a legal setting. A defense attorney, for example, would be careful to present his client in the best light possible. Defense attorneys work hard to keep unsavory aspects of the client's past or character from being revealed to the jury. But where a lawyer would seek to avoid presenting his client's warts, in science, the best way to defend a scientific theory is to present not only the supporting data, but also seek out the best arguments possible to refute your explanation. The best theoretical presentations include "my explanation would be wrong if..." sorts of statements, as did Darwin regarding natural selection in The Origin of Species. The scientist who conceals flaws in his theory is eventually going to lose, because someone else will ultimately expose them. In science, we publish our conclusions, which means we hold them up for later analysis.

"Truth" is something modern philosophers of science are very cautious about, tending to claim, in this post-Baconian world of ours, that "truth," is not something we can count on as permanent. We recognize that our explanations for natural phenomena may change; we do not assume that we have the "true" explanation. We are more or less confident about our explanations, rather than considering them "True", with a capital "T". We are quite confident, for example, that the earth goes around the sun, and that evolution took place, but we are less confident about how much of evolution punctuated equilibria explains compared to other models, or what precisely was the role of Neanderthal genetic variation in modern European gene pools.

Ashley Montagu (1984:9) remarked that "The scientist believes in proof without certainty, the bigot in certainty without proof." Whatever you think of his comment about creationists (and he was describing the young-earth, Biblical literalist creationists rather than using Johnson's sweeping definition of anyone who thinks God created), he accurately reflects the tentativeness of modern science.

But "truth" in law is an absolute; either a witness is telling the truth, or not. And, in a court of law, if it can be shown that part of a witness's testimony is false, then the judge can tell the jury to discount the entire testimony. Johnson, as a prosecuting attorney, falls naturally into this form of argumentation in his treatment of natural selection and other issues, as well. If natural selection is faulty, then evolution must fall; this omits the fact that natural selection is not the only conceivable mechanism for evolution. Here again, the general public is more attuned to a lawyer's way of thinking than to a scientist's. Time and again in the creationist literature one encounters the assumption that is some small observation is not accounted for by the theory, then the whole theory must go, regardless of how many other observations are explained by the theory, and regardless of how well the theory fits with other theories. The scientific creationists have, in fact, made a specialty of locating imagined "problems with evolution" and using them in creative ways to discredit the whole picture of descent with modification. If anatomist Charles Oxnard claims that the Australopithecines were not bipedal in the same way that modern humans are bipedal, then creationists distort his conclusion to say that there are no transitional human fossils. Therefore evolution did not occur. Never mind that whether or not Australopithecines are ancestral to modern humans has no bearing on whether Homo erectus or Neanderthals are. One cannot refute an entire evolutionary picture upon finding that one of the pieces of the puzzle was temporarily put in upside down.

Ecological Niches

Linguistic differences aside, it is also true that lawyers and scientists do very different things for a living, and consequently have a rather different world view. The job of a lawyer is not to find the truth, (that is the job of the judge or jury) but to defend (or prosecute) the client. Let me develop that idea a little further.

The jury or judge (known as the "fact finder," has the job of resolving the disposition of disputed facts — what "really happened." And by law, what "really happened," is what the fact finder concludes happened. In this resolution, many factors play roles. The background of the fact finder as well as the empirical evidence (and the skill of the lawyers) determine which facts are "true." Recently, a jury of middle-class whites decided in the Rodney King case that a group of white officers did not use excessive force in a beating of a black man stopped for a traffic offense. The empirical evidence included a videotape of the incident showing multiple blows to King after he was subdued. But as is clear in this case, the picture in the jury's mind was extremely important, rather than any Aristotelian eidos of what "really happened." It is clear that these fact finders brought with them to the decision considerable beliefs about the nature of police work, and the behavior of accused individuals of a particular sort. These beliefs were exploited skillfully by the lawyers for the accused — more skillfully than by the lawyers for the prosecution.

A lawyer doing his or her job will strive to bring the jury to his client's side. If the lawyers for the accused in the Rodney King case had done less, they would have been guilty of ethical violations. The standard is to vigorously argue on behalf of one's client, rather than to pursue an abstract "truth" or even "justice."

This is not a criticism of our legal system: we believe in our system of justice that the accused is innocent until proven guilty, and even those accused of the most heinous crimes deserve defense. In supporting the client, the lawyer may use any ethical means available. It is perfectly ethical for a lawyer to make ad hominem attacks on the opposing witnesses, to present incomplete information to a jury, to bring in irrelevant data, and of course use a wide panoply of rhetorical skills and tricks. Science, obviously, has different goals. But the lawyer's orientation should be kept in mind when analyzing Johnson's book, because he is a lawyer, he has titled is subject a trial, he pursues it as a trial, and his job is to prosecute Darwinism. Lots of things are "fair," from his point of view.

A good way for a lawyer to get the upper hand in a trial is to be sure that the definition of terms and description of events are shaded in one's client's favor: the creation of "straw men" appears to be fairly common in trials and during depositions. Thus Johnson defines terms to best suit his purposes. He uses "creation-science" to refer to the young-earth, six day creation variety, with which I would agree, but then seizes other vital terms for himself (p. 4):

"Creationism" means belief in creation in a more general sense. Persons who believe that the earth is billions of years old, and that simple forms of life evolved gradually to become more complex forms including humans, are 'creationists' if they believe that a supernatural Creator not only initiated this process but in some meaningful sense controls it in furtherance of a purpose. As we shall see, 'evolution' (in contemporary scientific usage) excludes not just creation-science but creationism in the broad sense. By "Darwinism" I mean fully naturalistic evolution, involving chance mechanisms guided by natural selection.

His "creationists" would thus include "theistic evolutionists," and he deliberately sets up evolution and Darwinism as anti-religious entities in the reader's eyes. Actually, evolution, Darwinism (evolution by natural selection) and science itself are no more irreligious than long-division. But Darwin on Trial would make no sense if theologically-neutral definitions were used.

Johnson uses these courtroom techniques in a "you can't win for losing" attack upon evolution. As a good lawyer, he creates doubt in the jury's mind. He will at length portray negatively some element of evolutionary theory, only to quietly admit later (after the doubt is sown) that the situation isn't exactly like that after all. He discusses how natural selection has been accused of being tautological, but then eventually admits that it can be formulated in such a way that it is not. By that time, however, (especially in the mind of the nonspecialist to whom the book is directed) the damage has been done.

A related legal maneuver is to add new criteria for evaluation if things are going badly for your side. So he argues that natural selection cannot produce new species, only to admit later that there are some cases where it looks as if indeed, natural selection has produced new species. Quickly he changes the criteria: even if it could be shown that natural selection can result in speciation, this wouldn't prove that natural selection could produce the whole tree of life!

This "add a new criterion" approach is especially prevalent when Johnson must deal with strong evidence for evolution. In lawyerly fashion, he generates the question in the reader's mind that something is fishy in the evidence, only later to admit that the evidence actually supports the evolutionist. But then he quickly slips in new criteria so that the anti-evolutionist position reigns at the end.

For example, in several passages he denounces the idea of transitional fossils. One of the most elegant transitional fossil series is the evolution of the mammalian jaw (S. Gould, "An Earful of Jaw", Natural History 3 p. 12ff., March 1990), and even Johnson calls it the "crown jewel of the fossil evidence for Darwinism" (p.75). (Actually, it is a "crown jewel" of evidence for evolution, rather than specifically the Darwinian mechanism, but here again Johnson confuses the two.) Johnson grudgingly admits that transitional fossils do exist to bridge the gap between reptile and mammal jaw types, but then denies that this proves evolution from the one to the other.

"On the other hand, there are many important features by which mammals differ from reptiles besides the jaw and ear bones, including the all-important reproductive systems. As we saw in other examples, convergence in skeletal features between two groups does not necessarily signal an evolutionary transition." (p. 76.)

But unfortunately for Johnson, although the reproductive system is not one of them (fossil uteri?), extra-mandibular structures showing intermediacy between reptiles and mammals do exist in the fossil record, which Johnson later is forced to admit. "It seems that the mammal-like qualities of the therapsids were distributed widely throughout the order," (p. 76.) Lest the reader now be persuaded that maybe evolution is OK after all, Johnson swiftly counter-punches. All the subgroups "are mutually exclusive as candidates for mammal ancestors. An artificial line of descent can be constructed, but only by arbitrarily mixing specimens from different subgroups" (p. 77).

The presence of intermediates, even extensive intermediates like those between reptiles and mammals, isn't sufficient to demonstrate evolution without new criteria being added. Johnson, like the creationists, insists on our showing the full range of fossil intermediates between two modern taxa: 80% reptile and 20% mammal, then 75% reptile and 25% mammal, and on and on.

Similarly, Johnson takes on the fossil whale, Basilosaurus, a particularly exciting fossil that not only has legs (found in other fossil whales, and even occasionally as vestigial structures in living ones) but actually has rudimentary feet. But whereas an evolutionist would hardly seek to find better evidence that whales are descended from terrestrial quadrupeds, Johnson briskly adds the requirement that we also provide him with evidence of step-by-step transitions between quadrupeds and whales that "permit deep diving, underwater communication by sound waves, and even to allow the young to suckle without taking in sea water." Well, when we find fossil uteri, perhaps we will also find evidence for fossilized underwater nursing. As in the old song, "Tell him to buy me an acre of land/Between the salt water and the salt sand." Johnson demands of us the impossible, but it reads quite well to the uninitiated.

Another classic example of his "you can't win for losing" style of argumentation is his treatment of the fossil reptile/bird intermediate, Archaeopteryx. Even if we found an unmistakable intermediate, which he admits the bird-like Archaeopteryx is, he still is not satisfied, and throws in another criterion before evolution can be accepted.

"Possibly birds did somehow develop from dinosaur predecessors, with Archaeopteryx as a way station, but even on this assumption we do not know what mechanism could have produced all the complex and interrelated changes that were necessary for the transformation (italics mine)." (p. 79)

No matter how fine the transitional form, he will not accept it unless we meet his demand for a complete explanation (from genetics? where?) of precise mechanisms producing the change!

All this sounds a bit shady to those of us outside the legal profession, but rhetorical tricks like these are considered perfectly ethical and in fact, are part of the responsibility of a lawyer to his or her client. Indeed, the stakes are high. Once the guilty or innocent decision is made by the judge or jury, and once the appeals are exhausted, that's the end of it. The judgment is collected and put in the bank, the client goes to prison, or maybe goes to the electric chair. The stakes are high in a legal case, and you want your champion to defend you to the best of his ability.

In science, there is never this finality of decision. The open-endedness of scientific discovery, the fact that we change our explanations, means that we can say that we are, indeed, searching for truth, though we are cognizant that at any given time, we might not have it, and in fact, may change again our ideas at a future time. In fact, in science, the tendency is that one never wins for long. Look at Piltdown: the conclusion that this specimen was an early human didn't last past the 1950's. One's conclusions are always subject to revision in science, which contrasts sharply with the situation in law.

I [ECS] recall when I began teaching anthropology that the big issue in paleoanthro was the "single species hypothesis" that only one hominid ever lived at one time. I recall, also, that its strongest proponent, Loring Brace, cheerfully admitted (or as cheerfully as one can, when one has spent 10 years of one's life promoting an idea) that the hypothesis was no longer valid after the discovery of critical fossils in East Africa. And more recently, the "out of Africa" interpretation of mitochondrial DNA data analysis has been called into question. The proponents of "African Eve" graciously admitted their computer algorithm was wrong. Back to the drawing board. Scientific explanations are not permanent. And only if you are an old-fashioned Baconian scientist, three hundred years out of date, is this worrisome. Unfortunately, most non-scientist Americans do not understand this basic fact of 20th century science. And few lawyers are scientists.

A final difference between law and science remains to be discussed. Of course scientific explanations (theories) change with new data, or new ways of looking at things. But explanations are changed when better explanations are proposed. One cannot expect one's colleagues to give up an explanation that "works" without providing an alternate explanation that explains all the phenomena explained by the old theory, and goes beyond to solve new problems.

Law has no such constraints. A lawyer only has to get his client off; he doesn't have to prove the butler did it. So Johnson takes great pride in denying that he is proposing an alternative to Darwinism. It is sufficient to him that he merely prosecute Darwin; he is, after all, a lawyer. But he is not going to persuade scientists that way. In science, if you are going to challenge the reigning paradigm, an established theory that explains enormous numbers of observations and ties in with numerous theories across several scientific fields, it behooves you to find something to replace it. The problem with insufficient numbers of neutrinos did not cause the Big Bang to be rejected; but if someone could come up with an explanation that explains as much as the Big Bang does, plus explains the number of neutrinos, then the Big Bang would be history. But one cannot just cry, "The Emperor has no clothes" in science: by our rules, you have to provide at least a bathrobe. If Johnson doesn't like it, let him take his basketball elsewhere.

Given these differences between law and science, I conclude that it is no special advantage for a lawyer to "take on" evolution, any more than it is an advantage for a hairdresser or a ballet dancer. Law is a fine and noble profession, but just because someone from a prestigious profession ventures out of his realm, doesn't mean we should take what he says seriously! The criterion for whether an outsider should be taken seriously as a critic of a field is knowledge about the subject. Does Johnson understand enough about evolution to be taken as a serious critic? The answer is no. He re-warms some old criticisms of the creationists, but adds nothing except rhetorical excess. And, of course, the creationists have been answered at length for several years now.

This is not to say, as Johnson does repeatedly, that evolutionary biology is closed to criticism. We no longer question whether change has taken place during the history of the universe than we question heliocentrism. But there are marvelous controversies about exactly what happened in evolution, which species is related to which, what the history of life entailed, and, especially, the proximate (not ultimate) mechanisms bringing this change about. How much does microevolution explain macroevolution? Are new mechanisms needed? How relevant are heterochrony and other ontogenetic processes to evolution? How much of evolution is explained by gradual vs. rapid evolution? What is the nature of species? Are they natural groups? Individuals? Or something else? Molecular taxonomy works; how about the molecular clock? How does cladistic systematics make us look at phylogeny? What causes extinction? To the degree that Johnson deals with any of these issues, he deals with them most superficially and misleadingly. Too bad. A student reading this book will come away with the idea that there is some sort of stuffy scientific establishment proclaiming an orthodoxy, against which no one may struggle. How wrong he is! And how dynamic — even scrappy — the field of evolutionary biology is!